.flex-container {
  display: flex;
  justify-content: center; // 主轴对齐方式
}

.main-flex-container {
  display: flex;
  flex-direction: column
}

.main-flex-container .item-flex-container {
  display: flex;
  justify-content: center;

}

.item-flex-container .triangle {
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 8px 8px 0;
  border-color: #cacaca transparent transparent;
  background: #f5f5f7;
}

.item-flex-container .plus-icon-btn {
  font-size: 20px;
  background: #3296fa;
  box-shadow: 0 2px 4px 0 rgba(0, 0, 0, 0.1);
  width: 30px;
  height: 30px;
  border-radius: 50%;
}
